Comb mold



May 3o, 1944. L, MAZZON, 2,349,977

COMB MOL D Filed March 18, 1941 2 Sheets-Sheet 2 Patented May 30, 1944 i COMB MOLD Lucien Mazzoni, Lyon, France; vested in the Alien Property Custodian Application March 18, 1941, Serial No. 384,011

ln France March 19, 1940 Y 9 Claims.

My invention relates to the manufacture of combs from plastic or articial materials such as cellulose derivatives or artificial resins.

Combsare usually made from suchmaterials by molding. In the cheaper articles. the teeth are directlytiobtained by molding without any subsequent operation, while in other cases the teeth are cut out in a rn'oldedblank. In the teeth obtained by molding the intermediate `spaces decrease in width from the tip to the bottom,fwhich. is an inconvenience for the user. This is avoided withteeth obtained by cutting; but `the cutting operation materially increases manufacturing costs.

-A-,rst object of my invention is to provide combs obtained by molding without any Subsequent operation, and wherein the spaces between the teeth areV regular in width from tip to bottom.

Another object of my invention is to provide a method ofmolding combs from plastic or `articial materials, wherein the spaces between the teeth are obtained by means of blades engaged. through the mold which are removed before the mold `is opened.`

A further object of my invention is a molding device for combs of plastic or artificial materials comprising a mold having a bottom supported by elastic means on a base provided with vertical blades partially engaged through the said bottom in such a vmanner that when the top of the mold is pressed on the bottom, the said blades are driven through the mold and are afterwards removed when the pressure of the top on the bottom is released` In the annexed drawings:

Fig. -1 shows a comb molded according to the known methods Without finishing operation.

Fig. 2. is an enlarged partial view thereof.

Figs. 3, 4 and 5 are sections thereof taken along lines III-III, IV--IV and V-V (Fig. 2).

Fig. 6 is a partial sectionoia blank obtained by molding in the known methods of manufacture involving a cutting operation.

Figflfis a similar section showing the crosssection of the teeth obtained from such a blank by cutting.

Fig. 8 is an enlarged partial view of the comb obtained.

Fig. 9 is a longitudinal section of a molding device according to my invention.

-l Fig. 10 is a view similar to Figli-9, 'but the top being pressed on the bottom fy l.

Figs. 11 and 12 are partial sections taken on lines XI--XI and XII-XII of Figs. 9 and l11).",

Figs. 13 and 14 are partial sections similar to Figs. 11 and 12, lbut showing the parts respectively when the pressure of the top on the bottom is released and when thel molded comb is disengaged from the mold.

Fig. 15 is a partial section of a modied mold at the open position.

Fig 16 shows on an enlarged scale a portion of Fig. 15.

Fig. 17 is a section taken on line XVII- XVII of Fig. 16.

Fig. ,18 is a view similar to Fig. 15. but at the i closed position of the mold.

Figs. 1 to 5 show a comb with two opposed series of teeth l fixed to the same back 2. This comb is directly obtained by molding according to the known methods. As it is well known,the mold is made of two parts,"the plane of the comb being coincident with the plane of the joint of the said parts.

In order to avoid breakage oi the teeth when the mold is being opened, it has been customary to give the teeth a cross-section more or less similar to a lozenge, as clearly shown in Figs. 4 and 5. Since the thickness a (Fig.` 3) of a tooth increases from the tip to the bottom, where it equals the thickness of the back 2, the dimensions of the cross-sectional lozenge also increase, as shown by Fig. 4 which corresponds to a line of section IV-IV (Fig. 2) inclined with respect to the back. The width b of the intermediate space between two consecutive teeth I therefore decreases from tip to bottom as shownA in Figs. 2 and 4, and with long and fine teeth said space may vanish in the vicinity of the back.

When using such a comb, the hair may be pinched in the narrower portions of the intermediate spaces. This kind of comb is therefore unsatisfactory. 4

The better combs are generally made by cutting the teeth in a molded blank. Fig. 6 shows the cross-section of such a blank wherein the teeth are not wholly formed and appear as ridges l' on both faces of a plain plate 3. The teeth are then finished by cutting by means of rotary cutters or the like and they finally appear as indicated in Figs. 'l and 8. The width b of the intermediate spaces between the successive teeth Ais regular from tip to bottom. The comb obtained is satisfactory, but its cost of manufacture is high owing to to the cutting operation which recesses 6 through slits I2 and I3.

i, but witliput any intermediate space between 5 the teeth, i. e. the mold formed by bottom 4 and top 5 when superimposed would produce a plain plate having the shape and the thickness of the comb of Fig. 1. 5

Bottom 4 is guided by vertical rods 'I fixed to I0 a horizontal base or support B and itis elastically supported thereon by springs A9 disposed around rods 1. Top 5 is also guided by rodslY and it is fixed to a vertically movable memberv I which may be, for instance, the movable head of a A15` molding'press.

Base A8 carries two rows of blades II disposed. in equidistant parallel relation, the upper part of each blade being engaged into a corresponding blades being so proportioned that at the open position of the mold (i. e. when the top '57.. is raised above bottom 4 as shown in Fig. il)v .they do not project in the corresponding recess 8.

l slit I 2 provided through bottom 4 and the said 20 Top is also provided with blind slitsto accom- 25 modate the upperv ends of blades II when the said top is lowered as indicated in Figs. and 12. l y

Blades II are so'fdisposed as to correspond with the intermediate spaces to be obtained bee prising a bottom portion having a molding recess' tween the successive teeth of the comb.

The operation is as follows: rIvop 5 is first pressed down on Springs 9 are compressed (Fig. 10) and bottom 4 is lowered whereby blades I I move upwardly-35` .with respect to :the mold. They project from bottom .4 and penetrate into slitslilv (Figs. 10 l -and`12). ,f -l

Y The plastic material or molding composition is 2,349,977 i v l It wnl'be understood that although the inven.-

tion has been described with lreference to 'a comb having rtwo rows of teeth, it may also be applied vto the manufacture of combs with but one series of teeth. Also the spacing of the teeth may be regular or irregular.

I claim:

1. A molding device for the manufacture of combs from plastic materials and the like comprising an openable mold having a, recess and a gate thereto into which plastic material is forced .under pressure to mold a blank having the contour and thickness of the comb to be obtained, said mold also'having a plurality of substantially parallel slits opening outwardly of the mold; and a plurality of blades, each of said blades being adapted to/ slide longitudinally through one of said slits and across the plane of the recess.

' 2. A molding device as claimed in claim 1, wherein the mold lis in two parts, the plane of the juncture of said parts being coincident with the meanlongitudinal plane of the comb to be obtained. i

3. A molding device as claimed in claim 1, wherein' the blades are movable perpendicularly with respect to the mean longitudinal plane of the comb to be obtained.

4. A molding device'for the manufacture of combs from plastic materials and the like comon its upper face and a plurality of substantially I parallel slits Vopening outwardly ofthe said bot'- ltom portion; a top' portion adapted to be pressed on said bottom portion, said -top portion having on its lower face aimolding recess adapted to cooperate with said first-named moldingv recess to mold a blank having the l'contour and thick- 3 ness of the comb to be obtained,` a gate leading thenintroduced into the mold under pressure 40 vthrough gate 20 'in the well-knownmanner. It ishard'ene'd in the mold by cooling, by polymerizatonlor 4,byany other appropriate means.

"Y ,"The"mold isthen opened by raising top 5. At

frst',.fsprings 9 maintain Abottom v4 pressed 45 against top 5, the mold being raised -as a whole,

whereby blades II move downwardly with respect tothe mold (Fig. 13) leaving void spaces I4 between the successive molded Ateeth I.Y The lat terbeing firmly maintained between parts; 4 and 50 5, there is no risk of breakage of the teeth.

Top 5 being further Yraised (Fig. 14) the mold is opened and the molded comb can be removed and used withoutrequiring any subsequent iinishing operation. i n The plain intermediate portions of the mold between slitsr I2 and I3 areY preferably concave as shown at I5 (Figs. 1i to 14), whereby the crosssection lof the teeth is rounded as indicated at,

` In the modification of Figs. 15 to 18 the blades e II are movable horizontally. The bottom part 4 of the mold need not be elastically supported on the press base.

Blades II are fixed to a transverse member I1 65 The mold is iirst closed as shown in Fig. 18 70 and blades II are pushed towards the molding The molding composition is introduced into the mold and hardened. Blades II are then disengaged and the mold is opened.

'forced into the `recesses` under pressure,

A5. A molding'device as' claimed in claim 4, wherein theplane ofthe juncture of the bottom ,and top portions is coincident with the mean longitudinal plane of the comb tobe obtained..

6. A molding device as claimed' in claiml 5.

Awherein the bladesare movable i transversely of and perpendicularly to the'mean longitudinal plane of the comb to be obtained.

7.A molding'device for the manufacture or' combs from plastic materials and the likecom-` prising in combination at fixed base; guiding means supported by said base; a bottom portion guided by said guiding means, said bottom portion having a molding recess on its upper face and a vplurality of substantially parallel vertical slits opened at both ends; spring means to elastically support said bottom on said base; a top portion `guided by said guiding means and adapty ed to be pressed on said b'ottomportion, said top portion vhaving; on its lowerface a molding recess adapted to cooperate with said first-named molding recess to mold a blank having the contour and thickness of the comb to be obtained and said top portion having a plurality of blind slits registering with the slits of said bottom portion and parallel therewith; a gate leading into the recesses and a plurality of vertical blades fixed to said base, said bladesv being adapted to .de longitudinally through said slits, and to exnd across the recesses when the top and botm portions Lare in contact vto receive the astic material forced into said recesses under essur`e, and said blades being so proportioned i not to project within the recess of said bot- `m portion when the latter is not lowered by le pressure of said top portion against the acm of said spring means.

8. In a molding device as claimed in claim 7, le surface of said bottom and top portions beween the successive slits being concave in crossction.

9. A mold for a comb comprising independently slidable top and bottom members having opposed complementary recesses conforming to the shape of a comb and its teeth, a gate connecting with said recesses and through which plastic material is fed, transverse slits in the mold members between the portions of the recesses conforming to the teeth of the comb, and xed blades completely occupying the slits when the members are slid into closed position preliminary to the introduction of the plastic material.

LUCIEN MAZZONI. 

